Heavy Metal Pollution Assessment Of Vegetables On Available In Qingdao And Remediation Ability Of Allium Sativum L. On Cadmium Or Lead Contaminated Soil

Based on the analysis and assessment of heavy metal content in vegetables of Qingdao main vegetable wholesale market, Allium sativum L. was taken as the experiment material for its highest enrichment amount of Cd and Pb. By flowerpot cultivation test and lab analysis, the physiological and ecological responses and remediation ability of Allium sativum L. on Cd or Pb contaminated soil were studied, with the purpose of providing scientific basis for the control and remediation of Cd or Pb contaminated soil. Main conclusions of the study are as follows:1. Heavy metal pollution situation of vegetables in Qingdao is more severe in winter than that in spring, and the main pollutants are Cd and Pb, their over standard rate are 37.5% and 25% respectively. Allium sativum L., which has the most amounts of Cd and Pb, is the most seriously polluted one in 6 categories of 24 kinds of vegetables. Cr,Cu and Zn content in vegetables did not exceed the national food hygienic standard.2. The same heavy metal conent varies significantly in different kinds of vegetables. Cd concent in bulb vegetable is the highest in winter, but root vegetable in spring. The Pb content in bulb vegetable is the highest in both winter and spring. Pb pollution of vegetable has little risk for the public health in Qingdao3. Allium sativum L. has high endurance and remediation ability to Cd contaminated soil. The physiological and ecological indices have no marked difference with the control while the concentration was lower than 100mg/kg; when Cd content was more than 20mg/kg, Cd content of the underground part of Allium sativum L. was more than 100mg/kg, but Cd content of the aboveground patt of Allium sativum L. was more than 100mg/kg when Cd content of soil was more than 200mg/kg. All enrichment coefficient of underground part are more than 2, and the enrichment coefficient of aboveground part is more than 1 when Cd content of soil was up to 500mg/kg.4. Allium sativum L. has poor endurance and remediation ability to Pb contaminated soil. When Pb content of soil was more than 1000mg/kg, the plant height, biomass, catalase activity of Allium sativum L. were all decreased significantly. The enrichment coefficient of aboveground part and underground part were all less than 1 in Pb contaminated soil.5. Primary analysis of ecological and economic benefit for phytoremediating Cd contaminated soils by Allium sativum L. indicates that Allium sativum L. has higher efficiency for the remediation of Cd contaminated soils, it is easy to spread and has wide application prospect.